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Biology subjects

Zhang, T.

Publications and source records attributed to Zhang, T..

At least 91 records · Page 5Linked to original sources

METTL14-dependent m6A modification restrains interferon signaling to prevent myocarditis and dilated Cardiomyopathy

The impact of inflammation on heart failure is increasingly recognized; but how cardiomyocyte restrains innate immune activation remains poorly defined, and nor does the role of N-methyladenosine (mA) modification in maintaining cardiac immune homeostasis. Here, we demonstrate that cardiomyocyte-specific deletion of the mA methyltransferase METTL14 triggers myocarditis, dilated cardiomyopathy, and premature lethality. Meanwhile, widespread hypomethylation and upregulation of innate immune and necroptosis-related transcripts in Mettl14-deficient hearts exemplified by IFN-1 and STAT1. Mechanistically, METTL14 deficiency promotes RIPK1 accumulation thereby priming cardiomyocytes for necroptosis and inflammatory cell death. Genetic ablation of IFN-I receptor Ifnar1 can largely rescue the processes and improve cardiac function and survival. Furthermore, METTL14 loss disrupts mitochondrial integrity and autophagy/mitophagy flux, suggesting mitochondrial dysfunction-driven innate immune activation upstream of IFN-I signaling. Collectively, these findings identify METTL14-mediated mA modification as a critical safeguard against cardiomyocyte-intrinsic IFN-I signaling and necroptosis and establish an epitranscriptomic-innate immune axis that drives inflammatory heart failure.

pathology↗

Systematic Validation of AlphaFold-Predicted Interactomes with LUCIA

Mapping protein-protein interactions (PPIs) at structural resolution is essential for understanding cellular machinery. While tools like AlphaFold enable proteome-wide structural predictions, the field lacks high-throughput experimental methods to verify these predictions at scale and establish empirical thresholds for confidence metrics, such as the widely used interface predicted Template Modeling (ipTM) score. We developed LUCIA (LUminescent Cell-free Interaction Assay), a rapid biochemical screening platform bypassing traditional cloning and protein expression to validate direct binary interactions within days. Applying this to herpesviruses, clinically relevant human pathogens with large proteomes, we generated an exhaustive computational interactome of 23,215 AlphaFold-predicted dimer models across three species (HSV-1, HCMV, and KSHV), accessible via our HerpesPPIs database. Using the HSV-1 interactome as a benchmark, testing 83 high-confidence predicted dimers with LUCIA yielded 23 novel, experimentally validated interactions. By calibrating AlphaFold metrics against this direct binding data, we demonstrated that an ipTM score [≥] 0.80 identifies bona fide interactions with a positive predictive value of 77%. To demonstrate the functional power of this pipeline, we characterized a previously unknown interaction between HSV-1 UL42 and UL8, linking the viral DNA polymerase and helicase-primase complexes. Structure-guided mutations at the predicted and LUCIA-verified UL42-UL8 interface strongly reduced binding in vitro and completely abolished viral replication in cell culture. Combining the scalable LUCIA platform with computational predictions enables researchers to rapidly translate atomic-level models into validated biological mechanisms without the need to solve experimental structures.

microbiology↗

Single-cell full-length transcriptome of human lung reveals genetic effects on isoform regulation beyond gene-level expression

Genetic regulation of splicing uniquely contributes to trait-associated genome-wide association studies (GWAS) signals. However, quantitative trait loci (QTL) analysis using short-read sequencing of bulk tissues fails to capture full-length and cell-type-specific isoforms. Here, we present an isoform-level lung cell atlas from 129 never-smoking Korean women using single-cell long-read RNA-sequencing, identifying abundant unannotated and cell-type-specific isoforms. Isoform-level signatures of 37 lung cell types display a larger difference and therefore improve cell-type classification compared to gene-level expression. Notably, isoform-QTLs (isoQTLs) detect unannotated and/or cell-type-specific isoforms with independent genetic regulation from expression-QTL (eQTL), supported by enriched splicing functional elements. IsoQTLs nominate susceptibility isoforms from previously unexplained lung function and cancer GWAS loci, via eQTL-independent signals. We highlight a potentially functional novel variant of PPIL6 in multiciliated cells underlying lung cancer risk through alternative splicing. This isoform-level resource advances our understanding of cell-type-specific isoform regulation and its contribution to lung traits and diseases.

genetics↗

Single-cell lung eQTL dataset of Asian never-smokers highlights the roles of alveolar cells in lung cancer etiology

Single-cell expression quantitative trait loci (sc-eQTL) analyses are powerful in identifying context-specific susceptibility genes from genome-wide association studies (GWAS) loci. However, few studies have comprehensively investigated cells of lung cancer origin in non-European populations. Here, we built a lung sc-eQTL dataset from 129 Korean women never-smokers with epithelial cell enrichment. eQTL mapping identified 2,229 genes with an eQTL in 33 cell types, including East Asian-specific findings when compared to predominantly European datasets. Integration with single-cell chromatin accessibility data demonstrated an enrichment of cell-type specific eQTLs in cell-type matched candidate enhancers, while shared eQTLs were more frequently found near promoters. Colocalization and transcriptome-wide association study unveiled 36 susceptibility genes from 22 cell types in 22 lung cancer loci, including 10 loci not achieving genome-wide significance in prior GWAS. Around 47% of these genes were from cells of the alveoli, underscoring their importance, especially in lung adenocarcinoma (LUAD) susceptibility. Focusing on the trajectory of alveolar epithelial cell regeneration, we detected 785 cell-state-interacting QTLs, which overlapped with 28% (10) of the identified susceptibility genes. Finally, we experimentally validated East Asian-and alveolar type 2 cell-specific eQTL of TCF7L2 underlying East Asian LUAD locus, 10q25.2. Consistent with its role as a Wnt/{beta}-catenin effector, TCF7L2 displayed significant effect on lung adenocarcinoma cell growth. Our data highlighted context-specific susceptibility genes, especially from alveolar cells of lung, contributing to lung cancer etiology.

genetics↗

A synonymous mutation in MSMEG_4729 occurs at a high frequency in spontaneous D29-resistant mutants of Mycobacterium smegmatis

Compassionate use of mycobacteriophage therapy highlights the promising potential of phage therapy as an alternative treatment option for antibiotic-resistant infections when conventional treatments fail. However, realizing the full potential of phage therapy requires addressing key challenges, including host immune responses, the limited arsenal of therapeutically-useful mycobacteriophages, and the emergence of phage resistance. Dissecting the mechanisms of phage resistance is critical for ensuring the effectiveness and sustainability of phage therapy. In this study, we demonstrate that exposure to the lytic mycobacteriophage D29 triggers diverse genetic changes in Mycobacterium smegmatis. A synonymous mutation in MSMEG_4729 arises frequently but is insufficient to confer D29 resistance on its own. Instead, we identified possible Lsr2-independent activation of the lipooligosaccharide (LOS) biosynthesis cluster in a D29-resistant mutant harboring this mutation. We have also detected the possible activity of MSMEG_3213, a type II methyltransferase associated with m6A modifications in M. smegmatis. Finally, we isolated defense escape mutants (DEMs) of D29 capable of overcoming resistance in a strain with the MSMEG_4729 synonymous mutation. This profiling of M. smegmatiss likely defensive arsenal against the therapeutically-useful mycobacteriophage D29 provides a roadmap for further investigations and rational engineering of next-generation mycobacteriophages to combat drug-resistant mycobacterial infections. Impact statementInterest in phage therapy has been gaining traction recently, which is largely due to the serious threat of antimicrobial resistance. However, the efficacy and sustainability of phage therapy is threatened by certain challenges, which includes the ever existent threat of phage resistance. In this study, we identified several likely factors involved in D29 interaction with the model mycobacterium M. smegmatis. These findings set a roadmap for future investigations that would guide rational phage engineering to expand the currently limited arsenal of therapeutically useful mycobacteriophages as well as improve the efficiency of existing ones.

microbiology↗

Systematic identification of tissue-conserved m6A sites reveals a stable epitranscriptomic regulatory layer controlling essential genes

Chemical modifications to RNA are fundamental regulators of cellular identity and function. Among these, N6-methyladenosine (m6A) is the most abundant mRNA modification in mammalian cell, governing major post-transcriptional processes. While conditional m6A dynamics are well studied, the extent and function of condition-independent, tissue-conserved (TC) m6A in humans remain unclear. Here we show that 5,945 TC sites are consistently methylated across 24 human tissues. These sites are enriched near stop codons, evolutionarily conserved, and characterized by distinct sequence signatures. RBM15/B are identified as candidate mediators of TC m6A deposition, and YTHDF1-3 and UPF1 are preferentially enriched at TC sites, supporting their role for m6A-linked mRNA decay. TC m6A sites mark 1,386 genes essential for core cellular processes like autophagy and homeostasis, showing stable expression and evolutionary constraint. Pan-cancer analysis reveals that TC m6A genes are disproportionately differentially expressed, alongside with altered RBM15/B expression, suggesting that disruption of this stable m6A layer may contribute to transcriptional changes in cancer.

molecular biology↗

A Deep Quantitative Proteome Turnover Platform for Human iPSC-derived Neurons

Quantitative evaluation of protein turnover in human neurons is crucial for understanding neuron homeostasis and guiding drug development for neurological diseases. However, measuring protein turnover in postmitotic neurons remains challenging due to the high dynamic range of protein half-lives and limited proteome coverage in SILAC (Stable Isotope Labeling by Amino acids in Cell culture) experiments. Despite broad applications of dynamic SILAC proteomics to measure protein turnover in rodent tissues and primary neurons, few studies have measured protein half-lives in human neurons with limited proteome coverage. Here, we established a comprehensive platform to quantify protein half-lives in human induced pluripotent stem cell (iPSC)-derived neurons. By integrating optimized dynamic SILAC labeling in human neuron cultures, extensive peptide fractionation, optimized data-dependent and data-independent LC-MS/MS acquisition methods, and a streamlined computational pipeline, we achieved deep and accurate measurement of 10,792 protein half-lives from 162,854 unique peptides. We then compared the protein turnover and abundances in iPSC-derived glutamatergic cortical neurons and spinal motor neurons, revealing globally conserved proteome dynamics alongside subtype-specific differences consistent with specialized neuronal functions. To enable broad community access, we created NeuronProfile (www.neuronprofile.com), an interactive web platform for exploring protein turnover, abundance, and subcellular location in human neurons. Together, this work provides a comprehensive analytical platform to assess human neuronal proteostasis and a foundational resource for neurological disease research and therapeutic development.

neuroscience↗

Volume regulation of cancer cells during osmotic pressure variation

Osmotic pressure is a fundamental physical determinant of cellular homeostasis, and its perturbation is recognized as a critical factor in cancer progression and therapy. However, whether cancer cells and normal cells respond to osmotic pressure changes differently remains unclear. Here, we subjected cancer and normal cells to osmotic shocks and compared their volume and traction force changes. Under hypotonic conditions, cancer cells recovered their volume and forces much more slowly than normal cells, although both cell types responded similarly to hypertonic shock. We found that actin-based cortical tension controlled the recovery speed; whereas myosin-mediated contractility tuned the volume change extent. Substrate stiffness also influenced the recovery process by altering cytoskeletal constraint. A theoretical model integrating adhesion energy, ion and water transport, and surface tension was developed. The results matched the experimental observations. Our work uncovered the distinct mechanobiological behaviors of cancer cells upon hypotonic shock, providing a mechanical framework for understanding cancer mechanisms that may inform the development of cancer therapeutics.

biophysics↗

Transient focal inactivation of the primary visual cortex abolishes saccadic inhibition

Most organisms are perpetually engaged in an active-perception cycle: at any moment, planning, executing, or recovering from a given own movement. In the oculomotor system, such a cycle is under a powerful, reflexive, and short-latency interruptive influence by exogenous sensory stimulation, but the multitude of possible pathways eventually converging on the final oculomotor control gateway make it unknown how reflexive oculomotor inhibition takes place. Here we show that transient focal inactivation of the primary visual cortex abolishes visually-driven saccadic inhibition, suggesting an unequivocal dominance of the geniculostriate visual pathway over this robust behavioral reflex. Using chronic lesions, computational modeling, and fine-grained eye-movement analyses, we then show that latent visual signals bypassing the geniculostriate pathway are still present, but may not be as central as previously anticipated. These results recast classic views on visual-motor reflexes, and motivate functional and theoretical investigations of the multiplicity of parallel input-output loops in the brain.

neuroscience↗

Modeling Multi-Modal Brain Connectomes for Brain Disorder Diagnosis via Graph Diffusion Optimal Transport Network

Network analysis of human brain connectivity provides a fundamental framework for identifying the neurobiological mechanisms that cause cognitive variations and neurological disorders. However, existing diagnostic models often treat structural connectivity (SC) as a fixed or optimal topological scaffold for functional connectivity (FC). This consequently overlooks the higher-order dependencies between brain regions that are critical for characterizing pathological alterations. Moreover, the distinct spatial organizations of SC and FC complicate their direct integration, as naive alignment methods may distort the inherent nonlinear patterns of brain connectivity. To address these limitations, we propose the Graph Diffusion Optimal Transport Network (GDOT-Net), which models disease-related topological evolution and achieves precise alignment between SC and FC. Unlike existing diffusion studies, the proposed model introduces an evolvable brain connectome modeling approach to infer the complex topological structure of brain networks, unveiling higher-order connectivity patterns linked to specific neuropsychiatric disorders. Furthermore, GDOT-Net incorporates a Pattern-Specific Alignment mechanism, leveraging optimal transport to align structural and functional topological representations in a geometry-aware manner. To capture nonlinear topological relationships between brain regions, a Neural Graph Aggregator Module was developed, which adaptively learns complex node interaction patterns in brain networks. By leveraging this module, GDOT-Net generates highly discriminative representations that form a robust basis for the precision diagnosis of brain disorders. Experiments on REST-meta-MDD and ADNI demonstrate that GDOT-Net surpasses SOTA methods in uncovering structural-functional misalignments and disorder-specific subnetworks. The source code is publicly available at this Link.

neuroscience↗

AAV-Mediated Dual-Gene Therapy Restores Metabolic Function in Mice with Propionic Acidemi

Background and AimsPropionic acidemia (PA) is a rare autosomal recessive disorder caused by mutations in PCCA or PCCB, which encode the two subunits of propionyl-CoA carboxylase (PCC). PCC deficiency causes toxic metabolite accumulation and multi-organ damage. Current management, including dietary restriction, pharmacological support, and liver transplantation, does not restore enzymatic activity. We developed a dual-gene adeno-associated virus (AAV) therapy that delivers both PCC subunits to treat both PA subtypes. MethodsWe generated a clinically relevant PCCA-R73W knock-in mouse model and administered AAV8 vectors encoding native human PCCA and PCCB under the control of a liver-specific thyroxine-binding globulin promoter (AAV8-TBG-hPCCA-P2A-hPCCB). Metabolite levels and organ safety were longitudinally assessed. ResultsDual-gene therapy produced dose-dependent reductions in plasma C3/C2 ratio, 3-hydroxypropionic acid, 2-methylcitric acid, and propionylglycine, and significantly outperformed single-gene (PCCA-only) therapy. Neonatal facial-vein injection achieved metabolic correction comparable to or better than adult treatment. The longitudinal follow-up revealed sustained efficacy over a 16-week period, with no signs of hepatotoxicity or adverse effects. ConclusionsSingle-dose, dual-gene AAV therapy achieves sustained metabolic correction and demonstrates long-term safety in a clinically relevant PA model, supporting its translational potential for both type I and type II propionic acidemia.

genetics↗

MERFISH 2.0, an ultra-sensitive single-cell spatial transcriptomics imaging chemistry across diverse tissue types

Spatial transcriptomics has emerged as a transformative approach for elucidating tissue architecture, cellular heterogeneity, and disease mechanisms by preserving the spatial context of gene expression in cells. Despite these advances, many spatial transcriptomic methods underperform in archival or clinically relevant specimens, particularly formalin-fixed, paraffin-embedded (FFPE) tissues, where RNA degradation and crosslinking hinder transcript detection. To address these challenges, we developed Multiplexed Error Robust Fluorescence In Situ Hybridization 2.0 (MERFISH 2.0), an optimized spatial transcriptomic imaging chemistry to enhance profiling of fragmented and highly crosslinked RNA. Across diverse human and mouse tissues preserved as fresh-frozen, fixed-frozen, and FFPE specimens, MERFISH 2.0 substantially increased transcript detection sensitivity by up to [~]8-fold relative to MERFISH 1.0 while preserving quantitative concordance (Pearson r [≥] 0.8 across tissues). In archived fresh-frozen human brain samples, MERFISH 2.0s enhanced sensitivity improved transcript recovery, enhanced cell type resolution and spatial analyses. In low quality archival FFPE human breast cancer specimen, MERFISH 2.0 revealed additional cell populations, novel cell clusters, refined tumor-immune architecture, and increased detection of gene-gene and cell-cell interactions relative to MERFISH 1.0, underscoring the impact of improved sensitivity on downstream spatial analysis. By substantially expanding robust transcript detection to degraded and archival samples, MERFISH 2.0 enables scalable, cohort-level spatial transcriptomic analysis across clinically relevant tissue collections.

genomics↗

Process optimization and antidepression multi-target mechanisms of Total Flavonoids from Hemerocallis citrina Baroni: An integrated approach combining DES-UAE, network pharmacology, and experimental validation

ObjectiveThis study aimed to establish a green and efficient ultrasonic-assisted deep eutectic solvent (DES) extraction method for total flavonoids from Hemerocallis citrina Baroni (TFHC) and to elucidate its multi-target antidepressant mechanism using an integrated strategy of network pharmacology, molecular docking, and in vitro validation. MethodsAn ultrasonic-assisted DES extraction using choline chloride-ethylene glycol was optimized via response surface methodology. The TFHC extract was profiled by UPLC-ESI-MS/MS. A network pharmacology approach was employed to predict core targets and pathways of TFHC constituents against depression, with key interactions validated by molecular docking. The neuroprotective effects of TFHC were evaluated in vitro using a corticosterone (CORT)-induced injury model in PC-12 cells, assessing cell viability (MTT assay) and levels of 5-HT, BDNF, TNF-, and CORT (ELISA). ResultsThe optimized DES extraction yielded 16.63 {+/-} 0.13 mg/g of TFHC. UPLC-ESI-MS/MS identified fourteen flavonoids, with quercetin, kaempferol, and rutin being most abundant. Network pharmacology revealed six core targets (AKT1, TNF, IL6, IL1{beta}, TP53, PTGS2) and implicated pathways including PI3K-AKT and TNF. Molecular docking confirmed strong binding affinities ([≤] -4.25 kcal/mol) between major flavonoids and core targets. In vitro, TFHC significantly alleviated CORT-induced cytotoxicity, restored 5-HT and BDNF levels, and suppressed TNF- and CORT elevation, with effects comparable or superior to fluoxetine. ConclusionsTFHC exerts antidepressant-like effects through a multi-target mechanism involving neuroinflammation suppression, neurotrophic support, and HPA axis modulation. The green DES extraction combined with mechanistic insights positions TFHC as a promising candidate for phytotherapeutic antidepressant development.

pharmacology and toxicology↗

Likely role of promoter reconstitution in Mpr-mediated D29 resistance by Mycobacterium smegmatis

The multi-copy phage resistance gene (mpr) of M. smegmatis is a major factor in resistance to the lytic mycobacteriophage D29. Mpr is a membrane-bound exonuclease that cleaves phage DNA post injection, hence blocking downstream stages in the phage infection cycle. The mechanism of resistance allows for adsorption, is non-abortive and independent of any mutation in the gene. Rather, it depends on overexpression of a wild type copy of the gene. However, the underlying factor behind mpr overexpression in spontaneous D29-resistant mutants of M. smegmatis remained elusive. Here, we report that D29 infection triggers insertion sequence (IS) rearrangements, including the transposition and integration of IS6120 directly upstream of mpr. Mutants with IS6120 integration upstream of mpr show highly elevated Mpr expression. Whole genome sequence analysis reveals that IS6120 introduced a putative transcription factor-binding site and a canonical -35 promoter element at the integration site, hence reconstituting a fuller promoter (rcp) than the original promoter (wtp) at the site. Promoter reporter assays suggest that rcp is a far stronger promoter than wtp, implying that elevated mpr expression in D29-resistant mutants with this transposition event could be due to promoter reconstitution. While strains with this transposition event appear to grow normally, rcp-driven, vector-borne Mpr overexpression appears to be toxic as it barely allows for colony formation on agar plates. This study reports a previously unknown factor likely behind mpr regulation in M. smegmatis, adding to the existing knowledge of mycobacterial anti-phage defense mechanisms and guiding rational phage engineering efforts for therapeutic applications.

microbiology↗

A druggable redox switch on SHP1 controls macrophage inflammation

Immunological proteins are major disease targets, yet most remain undrugged. Post-translational redox modification of cysteine residues has emerged as an important mode of immune cell regulation, particularly in macrophage cytokine responses. Here, we develop a strategy for systematic discovery and small-molecule functionalization of redox-regulated cysteines on immunological proteins. Using deep redox proteomics, we annotate 788 in vivo redox-regulated cysteines across diverse immune-relevant protein domains. We demonstrate how these sites enable cysteine-directed pharmacology through discovery of a novel cysteine activation site on the immune regulator SHP1. Targeting Cys102, we develop a highly selective covalent agonist, SCA, which binds the N-SH2 domain to relieve autoinhibition and activate SHP1. In mouse and human macrophages, SCA selectively engages SHP1 Cys102, antagonizing IRAK signaling and LPS-induced pro-inflammatory cytokine production. Together, this work identifies a druggable cysteine redox switch controlling macrophage cytokine responses and provides a compendium of redox-regulated sites for therapeutic development.

biochemistry↗

Visual semantic tuning across the cortex shifts between tasks

Attention is a powerful mechanism that dynamically optimizes brain representations to prioritize behaviorally-relevant information. While previous studies focusing on single tasks have demonstrated that attention shifts tuning towards attended targets, real-world behavior often requires humans to switch between tasks with different demands. How does visual semantic tuning in the human brain shift to support the behavioral demands of different naturalistic tasks? To answer this question, we used voxelwise encoding models to compare visual semantic tuning across the human cerebral cortex between two distinct naturalistic tasks, movie watching and navigation. Results show that visual semantic tuning in the cortex differed substantially between tasks. Principal component analysis reveals that during navigation, tuning shifts increase the representation of vehicles and traffic signs compared to movie watching, and that these shifts were localized to distinct functional networks. These tuning shifts reconfigure the human brains representations of object categories based on their behavioral relevance. These findings demonstrate that visual semantic tuning in the brain dynamically shifts towards task-relevant information across naturalistic tasks, optimizing functional representations to achieve diverse behavioral goals. Significance statementIn real-world situations, we switch between many tasks with behaviorally distinct goals that require us to attend to different targets. Here we show that visual semantic tuning across the human cortex shifts between passive movie-watching and active navigation. These tuning shifts increase the representation of behaviorally-relevant objects, such as cars during navigation. Tuning shifts towards different object categories are distributed across distinct functional networks, suggesting that they engage different cognitive mechanisms. These results show that visual semantic tuning in the human brain is highly task-dependent and is optimized to represent behaviorally-relevant information.

neuroscience↗

Pharmacological recruitment of a VTA glutamatergic arousal circuit by the natural product BN3 drives broad-spectrum emergence from general anesthesia

Pharmacological control of emergence from general anesthesia remains strikingly limited. Clinically available antagonists are largely drug-class specific, leaving recovery dependent on anesthetic clearance rather than to an actively programmable switch in brain state. Through phenotypic screening of a structurally diverse natural-product library, we identified BN3 (L-(-)-camphor) as a broad-spectrum emergence agent. BN3 robustly shortened recovery from propofol anesthesia across species--from mice and rats to rabbits, dogs, and rhesus monkeys--and remained effective after continuous infusion. In rodents, BN3 also accelerated emergence from mechanistically distinct anesthetics, including etomidate, remimazolam, sodium {gamma} - hydroxybutyrate, midazolam, ketamine, sodium pentobarbital, and isoflurane. EEG recordings revealed a rapid cortical shift from slow-wave dominance to a wake-like high-frequency spectrum. Mechanistically, BN3 preferentially recruited ventral tegmental area (VTA) glutamatergic neurons: chemogenetic silencing abolished the BN3-evoked EEG spectral shift and strongly attenuated behavioral acceleration of emergence, whereas optogenetic activation of these neurons was sufficient to promote recovery. BN3 increased glutamate release in the nucleus accumbens and medial prefrontal cortex, and projection-specific inhibition of VTA[->]NAc or VTA[->]mPFC outputs blunted BN3-induced emergence. These findings define a VTA-centered glutamatergic arousal circuit that can be pharmacologically recruited as a common gateway for anesthetic-independent emergence.

neuroscience↗

Tirzepatide improves pancreatic β-cell function in mice and patients with type 2 diabetes.

The dual incretin receptor agonist tirzepatide improves {beta}-cell function in T2D patients, but the underlying mechanism remains unclear. This study aimed to elucidate the molecular pathway through which tirzepatide restores {beta}-cell functional improvement. High-fat diet (HFD)-fed C57BL/6J mice were treated with vehicle, a GIP analogue, semaglutide or tirzepatide. Tirzepatide significantly reduced body weight and improved glucose tolerance in HFD-fed mice without altering {beta}-cell mass, proliferation, or apoptosis. Instead, tirzepatide reversed {beta}-cell dedifferentiation, as indicated by reduced ALDH1A3 expression and restored levels of the identity transcription factors PDX1 and MAFA. Single-cell RNA sequencing (scRNA seq) and in vitro studies revealed that tirzepatide up-regulated FOXO1, reactivating the FOXO1-PDX1/MAFA axis. In T2D patients, tirzepatide improved glycemic control, reduced insulin demand, increased HOMA-{beta}, and decreased HOMA-IR. Improvement in HOMA-{beta} correlated positively with baseline insulin resistance. Hence, our study suggested that tirzepatide restores {beta}-cell function in T2D by reprogramming stressed {beta} cells and re-establishing {beta}-cell identity through FOXO1-dependent transcriptional reactivation. These findings provide a mechanistic basis for the superior efficacy of dual incretin receptor agonism in T2D management. ARTICLE HIGHLIGHTSO_LITirzepatide restores {beta} cell identity and function without altering {beta} cell mass in HFD induced diabetic mice. C_LIO_LITirzepatide reverses {beta}-cell dedifferentiation and restores key {beta}-cell transcription factors (PDX1, MAFA) through reactivation of the AKT-FOXO1 signaling pathway. C_LIO_LITirzepatide increases HOMA-{beta} and decreases HOMA-IR in T2D patients, and improvements in HOMA-{beta} positively correlate with baseline insulin resistance. C_LIO_LIThese results demonstrate that tirzepatides therapeutic benefits are not only metabolic but also involve direct restoration of {beta}-cell identity and function. This highlights {beta}-cell reprogramming as a novel therapeutic avenue, thus supporting the broader clinical adoption of dual incretin receptor agonists. C_LI

physiology↗